Webster was a strong proponent of spelling reform for reasons both philological and nationalistic. Many spelling changes proposed in the US by Webster himself, and in the early 20th century by the Simplified Spelling Board, never caught on. Among the advocates of spelling reform in England, the influences of those who preferred the Norman (or Anglo-French) spellings of certain words proved decisive. Subsequent spelling adjustments in the UK had little effect on present-day US spelling, and vice versa. While in many cases American English deviated in the 19th century from mainstream British spelling, on the other hand it has also often retained older forms.

The spelling systems of Commonwealth countries, for the most part, closely resemble the British system. In Canada, however, while most spelling is "British", many "American" spellings are also used. Additional information on Canadian and Australian spelling is provided throughout the article.

Aeroplane, originally a French loanword, is the older spelling. According to the OED,[1] "[a]irplane became the standard U.S. term (replacing aeroplane) after it was adopted by the National Advisory Committee for Aeronautics in 1916. Although A. Lloyd Jones recommended its adoption by the BBC in 1928, it has until recently been no more than an occasional form in British English." In the British National Corpus,[2]aeroplane outnumbers airplane by more than 7:1. The case is similar for UK aerodrome[3] and US airdrome,[4] although both of these forms are now obsolescent. The prefixes aero- and air- both mean air, and each of the two forms is found in numerous words, including many relating to aeroplanes and aviation. Thus, for example, the first appears in aeronautics, aerostatics and aerodynamics, and so on, while the second occurs (invariably) in aircraft, airport, airliner, airmail, etc. In Canada, Airplane is used more commonly than aeroplane, although aeroplane is not unknown, especially in parts of French Canada (the current French term is, however, avion—aéroplane designating in French the plane ancestor). Both Canada and Australia use aerodrome as a technical term.

The spelling aluminium is the international standard in the sciences (IUPAC). The American spelling is nonetheless used by many American scientists. Humphry Davy, the element's discoverer, first proposed the name alumium, and then later aluminum. The name aluminium was finally adopted to conform with the -ium ending of metallic elements.[5] Canada as US, Australia as UK.

In sense "slightly insane", "crazy", "foolish",[6] which has limited currency in American English. Both forms originated in 19th century England from other senses: barmy meant "frothing [as of beer]"; balmy means "warm and soft [as of weather]". British barmy is generally misheard in North America as balmy.

In the US, according to the Merriam-Webster Collegiate Dictionary and the American Heritage Dictionary, the British spelling is an also-ran, yet the pronunciation with second-syllable stress is a common variant. Both versions are known almost equally in Canada, with the British version being used slightly more often.

Mother. Mom is sporadically regionally found in the UK (West Midlands English); some British dialects have mam,[12] and this is often used in Irish and Welsh English. In the US region of New England, especially in the case of the Boston accent, the British pronunciation of mum is often retained, while it is still spelt mom. Canada has mom and mum; in Australia, mum is the word.

According to major dictionaries, both forms can occur in both dialects, although snigger can cause offense in the US due to the similarity to nigger. In Canada snigger can have malicious connotations; in Australia snigger prevails, as in the UK.[16]

In British English the standard usage is speciality, but specialty occurs in the field of medicine,[17] and also as a legal term for a contract under seal. In Canada, specialty prevails; in Australia both are current.[18]

Latin-derived spellings

-our, -or

Most words ending in unstressed -our in the United Kingdom (e.g., colour, flavour, honour, armour) end in -or in the United States (i.e., color, flavor, honor, armor). Where the vowel is unreduced, this does not occur: contour, paramour, troubadour, are spelled thus everywhere.
Most words of this category derive from Latin non-agent nouns having nominative -or; the first such borrowings into English were from early Old French and the ending was -or or -ur.[19] After the Norman Conquest, the termination became -our in Anglo-French in an attempt to represent the Old French pronunciation of words ending in -or,[20] though color has been used occasionally in English since the fifteenth century.[21] The -our ending was not only retained in English borrowings from Anglo-French, but also applied to earlier French borrowings.[22] After the Renaissance, some such borrowings from Latin were taken up with their original -or termination; many words once ending in -our (for example, chancellour and governour) now end in -or everywhere. Many words of the -our/-or group do not have a Latin counterpart; for example, armo(u)r, behavio(u)r, harbo(u)r, neighbo(u)r; also arbo(u)r meaning "shelter", though senses "tree" and "tool" are always arbor, a false cognate of the other word. Some 16th and early 17th century British scholars indeed insisted that -or be used for words of Latin origin (e.g. color[21]) and -our for French loans; but in many cases the etymology was not completely clear, and therefore some scholars advocated -or only and others -our only.[23]

Webster's 1828 dictionary featured only -or and is generally given much of the credit for the adoption of this form in the US. By contrast, Dr Johnson's 1755 dictionary used the -our spelling for all words still so spelled in Britain, as well as for emperour, errour, governour, horrour, tenour, terrour, and tremour, where the u has since been dropped. Johnson, unlike Webster, was not an advocate of spelling reform and for the most part simply recorded what he found. For example, documents [2] from the Old Bailey, the foremost court in London, support the view of the OED that by the 17th century "colour" was the settled spelling. Those English speakers who began to move across the Atlantic would have taken these habits with them and H L Mencken makes the point that, "honor appears in the Declaration of Independence, but it seems to have got there rather by accident than by design. In Jefferson’s original draft it is spelled honour. "[24] Examples such as color, flavor, behavior, harbor, or neighbor scarcely appear in the Old Bailey's court records from the 17th and 18th century, whereas examples of their -our counterparts are generally numbered in hundreds. One notable exception is honor: honor and honour were equally frequent down to the 17th century,[25]Honor still is, in the UK, the normal spelling as a person's name.

Derivatives and inflected forms. In derivatives and inflected forms of the -our/or words, in British usage the u is kept before English suffixes that are freely attachable to English words (neighbourhood, humourless, savoury) and suffixes of Greek or Latin origin that have been naturalized (favourite, honourable, behaviourism); before Latin suffixes that are not freely attachable to English words, the u can be dropped (honorific, honorist, vigorous, humorous, laborious, invigorate), can be either dropped or retained (colo(u)ration, colo(u)rize), or can be retained (colourist).[26] In American usage, derivatives and inflected forms are built by simply adding the suffix in all environments (favorite, savory, etc.) since the u is absent to begin with.

The name of the herb savory is thus spelled everywhere, although the probably related adjective savo(u)ry, like savour, has a u in the UK. Honor (the name) and arbor (the tool) have -or in Britain, as mentioned above. As a general noun, rigour (IPA: /ˈrɪgə(ɹ)/) has a u in the UK; the medical term rigor (often IPA: /ˈraɪgɔː(ɹ)/) does not.

Commonwealth usage. Commonwealth countries normally follow British usage. In Canada -or endings are not uncommon, particularly in the Prairie Provinces, though they are rarer in Eastern Canada.[28] In Australia, -or terminations enjoyed some use in the 19th century, and now are sporadically found in some regions,[29] usually in local and regional newspapers, though -our is almost universal. The name of the Australian Labor Party, founded in 1891, is a remnant of this trend.

-re, -er

In British usage, some words of French, Latin, or Greek origin end with a consonant followed by -re, with the -re unstressed and pronounced /ə(ɹ)/. Most of these words have the ending -er in the US. The difference is most common for words ending -bre or -tre: British spellings theatre, goitre, litre, lustre, mitre, nitre, reconnoitre, saltpetre, spectre, centre, titre; calibre, fibre, sabre, and sombre all have -er in American spelling. The ending -cre, as in acre, lucre, massacre, mediocre, is preserved in American English, to indicate the c is pronounced /k/ rather than /s/. After other consonants, there are not many -re endings even in British English: louvre, manoeuvre after -v-; meagre, ogre after -g-; euchre, ochre, sepulchre after -ch-. In the US, ogre and euchre are standard; manoeuvre and sepulchre are usually maneuver and sepulcher; and the other -re forms listed are variants of the equivalent -er form.

The e preceding the r is retained in US derived forms of nouns and verbs, for example, fibers, reconnoitered, centering, which are, naturally, fibres, reconnoitred and centring respectively in British usage. It is dropped for other inflections, for example, central, fibrous, spectral. However such dropping cannot be regarded as proof of an -re British spelling: for example, entry derives from enter, which has not been spelled entre for centuries.

Exceptions. Many other words have -er in British English. These include Germanic words like anger, mother, timber, water,[30], and Romance words like danger, quarter, river. Some -er words, like many -re words, have a cognate in Modern French spelled with -re: among these are chapter, December, diameter, disaster, enter, letter, member, minister, monster, number, oyster, powder, proper, sober, tender.

Theater is the prevailing American spelling and is used by America's national theater as well as major American newspapers such as the New York Times (theater section) to refer to both the dramatic arts as well as to buildings where performances take place; yet theatre is also current, witness Broadway and The New Yorker. Some places in the United States have "Centre" in their names (i.e. Rockville Centre, New York), named both before and after spelling reform, and there are very occasional uses of "Center" in England [3]). For British accoutre(ment), US practice varies: Merriam-Webster favours the -re spelling,[31] American Heritage the -er spelling.[32]

More recent French loanwords retain an -re spelling in American English. These are not exceptions when a French-style pronunciation is used (/ɹ(ə)/ rather than /ɚ/), as with double-entendre, genre, or oeuvre. However, the unstressed /ɚ/ pronunciation of an -er ending is used more or less frequently with some words, including cadre, macabre, maître d', Notre Dame, piastre, and timbre.

Commonwealth usage.[33] The -re endings are standard throughout the Commonwealth. The -er spellings are recognized, as minor variants, only in Canada.

-ce, -se

Nouns ending in -ce with -se verb forms: American English and British English both retain the noun/verb distinction in advice / advise and device / devise, but American English has abandoned the distinction with licence / license and practice / practise (where the two words in each pair are homophones) that British spelling retains. American English uses practice and license for both meanings.

Commonwealth usage. Canadian English generally follows British usage for defence and offence and mostly for licence/license as well, although licence is sometimes used for the verb[citation needed]; both pretence[citation needed] and pretense are found, as are practice and practise for both noun and verb[citation needed]. Rest of the Commonwealth as UK.

-xion, -ction

The spellings connexion, inflexion, deflexion, reflexion, genuflexion are now somewhat rare in everyday British usage, but are not used at all in the US: the more common connection, inflection, deflection, reflection, genuflection have almost become the standard internationally. According to the Oxford English Dictionary the older spellings are more etymologically conservative, since these four words actually derive from the Latin root -xio. The US usage derives from Webster who discarded -xion in favour of -ction for analogy with such verbs as connect.[34]

Connexion has found preference again amongst recent British government initiatives such as Connexions (the national careers and training scheme for school early leavers). Until the early 1980s, The Times of London also used connexion as part of its house style.[35] It is still used in legal texts and British Methodism retains the eighteenth century spelling connexion to describe its national organization, for historical reasons.

In both forms, complexion (which comes from the stem complex) is standard and complection is not.[36] However, the adjective complected (as in "dark complected"), although sometimes objected to, can be used as an alternative to complexioned in the US,[37] but is quite unknown in this sense in the UK, although there is an extremely rare usage to mean complicated (OED). Note, however, that crucifiction is an error in either form of English; crucifixion is the correct spelling.

Greek-derived spellings

-ise, -ize

American spelling accepts only -ize endings in most cases, such as organize, recognize, and realize. British usage accepts both -ize and the more French-looking -ise (organise, recognise, realise). However, the -ize spelling is now rarely used in the UK in the mass media and newspapers, and is hence often incorrectly regarded as an Americanism,[38] despite being preferred by some authoritative British sources, including Fowler's Modern English Usage and the Oxford English Dictionary, which until recently did not list the -ise form of many individual words, even as an alternative. Indeed, it firmly deprecates this usage, stating, "[T]he suffix…, whatever the element to which it is added, is in its origin the Gr[eek] -ιζειν, L[atin] -izāre; and, as the pronunciation is also with z, there is no reason why in English the special French spelling in -iser should be followed, in opposition to that which is at once etymological and phonetic."[39] Noah Webster rejected -ise for the same reasons.[40]

The -ise form is used often[citation needed], but seemingly not always[citation needed] by the British government and is more prevalent in common usage within the UK today; the ratio between -ise and -ize stands at 3:2 in the British National Corpus.[41] The OED spelling (which can be indicated by the registered IANA language tagen-GB-oed), and thus -ize, is used in many British-based academic publications, such as Nature, the Biochemical Journal and The Times Literary Supplement. In Australia and New Zealand -ise spellings strongly prevail; the Australian Macquarie Dictionary, among other sources, gives the -ise spelling first. The -ise form is preferred in Australian English at a ratio of about 3:1 according to the Macquarie Dictionary. Conversely, Canadian usage is essentially like American,[42] although -ise is occasionally found in Canada,[citation needed][43] Worldwide, -ize endings prevail in scientific writing and are commonly used by many international organisations.

-yse, -yze

The distribution of -yse and -yze endings, as in analyse / analyze, is different: the former is British, the latter American. Thus, UK analyse, catalyse, hydrolyse, paralyse; US analyze, catalyze, hydrolyze, paralyze. However, analyse was commonly spelled analyze from the first — a spelling also accepted by Samuel Johnson; the word, which came probably from French analyser, on Greek analogy would have been analysize, from French analysiser, from which analyser was formed by haplology.[48] In Canada, -yze prevails; in Australia, -yse stands alone. Unlike -ise/-ize, neither of the endings has any resemblance to the Greek original ending. The Greek verb from which the word λύσις (lysis) (and thus all its compound words) derives, is λύειν (lyein).

-ogue, -og

Some words of Greek origin, a few of which derive from Greek λόγος, can end either in -ogue or in -og: analog(ue), catalog(ue), dialog(ue), demagog(ue), pedagog(ue), monolog(ue), homolog(ue), etc. In the UK (and generally in the Commonwealth), the -ogue endings are the standard. In the US, catalog has a slight edge over catalogue[49] (note the inflected forms, cataloged and cataloging vs. catalogued and cataloguing); analog is standard for the adjective, but both analogue and analog are current for the noun; in all other cases the -gue endings strongly prevail,[50] except for such expressions as dialog box in computing, which are also used in the UK. Finally, in Canada and Australia as well as the US analog has currency as a technical term[51] (e.g. in electronics, as in "analog computer" and many video game consoles might have an analog stick).

The Ancient Greekdiphthongs <αι> and <οι> were transliterated into Latin as <ae> and <oe>. The ligatures æ and œ were introduced when the sounds became monophthongs, and later applied to words not of Greek origin, in both Latin (for example, cœli) and French (for example, œuvre). In English, which has imported words from all three languages, it is now usual to replace Æ/æ with Ae/ae and Œ/œ with Oe/oe. In many cases, the digraph has been reduced to a single e in all varieties of English: for example, oeconomics, praemium, and aenigma.[53] In others, it is retained in all varieties: for example, phoenix, and usually subpoena.[54] This is especially true of names: Caesar, Oedipus, Phoebe, etc. There is no reduction of Latin -ae plurals (e.g. larvae); nor where the digraph <ae>/<oe> does not result from the Greek-style ligature: for example, maelstrom, toe. British aeroplane is an instance (compare other aero- words such as aerosol). The now chiefly North American airplane is not a respelling but a recoining, modelled on airship and aircraft. Airplane dates from 1907,[55] at which time aero- was trisyllabic, often written aëro-.

Commonwealth usage. In Canada, e is usually preferred over oe and often over ae as well; in Australia and elsewhere, the spellings with just e are increasingly used.[56]Manoeuvre is the only spelling in Australia and the most common one in Canada, where maneuver and manoeuver are also sometimes found.[57]

Internationally, the American spelling is closer to the way most languages spell such words; for instance, almost all Romance languages (which tend to have more phonemic spelling) lack the ae and oe spellings (a notable exception is French), as do Swedish, Polish, and others, while Dutch uses them ("ae" is rare and "oe" is the normal representation of the sound IPA: [u], while written "u" represents either the sound y or ʏ in IPA). Danish and Norwegian retain the original ligatures. German, through umlauts, retains its equivalent of the ligature, for when written without the umlaut, words resemble the British usage (i.e. ä becomes ae and ö becomes oe). Similarly, Hungarian uses "é" as a replacement for "ae" (although it becomes "e" sometimes), and the special character "ő" (sometimes "ö") for "oe".

Compounds and hyphens

British English often prefers hyphenated compounds, such as counter-attack, whereas American English discourages the use of hyphens in compounds where there is no compelling reason, so counterattack is much more common. Many dictionaries do not point out such differences. Canadian and Australian usage is mixed, although Commonwealth writers generally hyphenate compounds of the form noun plus phrase (such as editor-in-chief).[58]

Doubled consonants

Doubled in British English

The final consonant of an English word is sometimes doubled when adding a suffix beginning with a vowel. Generally this occurs only when the word's final syllable ends with a single vowel followed by a single consonant, and the syllable is stressed; but in British English, a final -l is often doubled even when the final syllable is unstressed.[59] This exception is no longer usual in American English, apparently because of Noah Webster.[60] The -ll- spellings are nonetheless still regarded as acceptable variants by both Merriam-Webster Collegiate and American Heritage dictionaries.

The British English doubling is required for all inflections (-ed, -ing, -er, -est) and for noun suffixes -er, -or. Therefore, British counsellor, cruellest, modelling, quarrelled, signalling, traveller; American usually counselor, cruelest, modeling, quarreled, signaling, traveler.

parallel keeps a single -l- in British English, as in American English (paralleling, unparalleled), to avoid a cluster -llell-.

Words with two vowels before l are covered where the first either acts as a consonant (Br equalling, initialled; US usually equaling, initialed) or belongs to a separate syllable (Br fu•el•ling, di•alled; US usually fu•el•ingdi•aled)

The distinction applies to victualler/victualer in spite of the irregular pronunciation IPA: /ˈvɪtlə(ɹ)/

British woollen is a further exception (US woolen); also, wooly is accepted in America though woolly dominates in both.[61]

Endings -ize/-ise, -ism, -ist, -ish usually do not double the l in British English: normalise, dualism, novelist, devilish

American English has unstressed -ll-, as in the UK, in some words where the root has -l. These are cases where the alteration occurs in the source language, often Latin. (Examples: bimetallism, cancellation, chancellor, crystallize, excellent, tonsillitis)

But both dialects have compelled, excelling, propelled, rebelling (notice the stress difference); revealing, fooling (double vowel before the l); hurling (consonant before the l).

Among consonants other than l, practice varies for some words, such as where the final syllable has secondary stress or an unreduced vowel. In the US, the spellings kidnaped and worshiped, introduced by the Chicago Tribune in the 1920s,[63] are common alongside kidnapped and worshipped, the only standard British spellings.

Miscellaneous:

British calliper or caliper; American caliper.

British jewellery; American jewelry. The standard pronunciations (UK IPA: /ˈdʒuː(ə)lri/, US IPA: /ˈdʒu(ə)lri/)[64] do not reflect this difference. According to Fowler, jewelry used to be the "rhetorical and poetic" spelling in the UK. Canada has both, but jewellery is most used. Likewise, Commonwealth (including Canada) has jeweller and US has jeweler for a jewel(le)ry retailer.

Doubled in American English

Conversely, there are words where British writers prefer a single l and Americans usually use a double l. These include
wil(l)ful, skil(l)ful, thral(l)dom, appal(l), fulfil(l), fulfil(l)ment, enrol(l)ment, instal(l)ment. In the UK ll is used occasionally in distil(l), instil(l), enrol(l) and enthral(l)ment, and often in enthral(l). Former spellings instal, fulness, and dulness are now rare.[65] The Scottish tolbooth is cognate with toll booth, but has a specific distinct sense.

The preceding words have monosyllabic cognates always written with -ll: will, skill, thrall, pall, fill, roll, stall, still. Comparable cases where a single l occurs in American English include full→useful, handful; all→almighty, altogether; null→annul, annulment; till→until; well→welfare, welcome; chill→chilblain; and others where the connection is less transparent. Note that British fulfil and American fulfill are never fullfill or fullfil.

Dr Johnson wavered on this issue; his dictionary of 1755 lemmatizes distil and instill, downhil and uphill.[66]

Dropped e

British English sometimes keeps silent e when adding suffixes where American English does not.

British prefers ageing,[67] American usually aging (compare raging, ageism). UK often routeing;[68] US usually routing (for route; rout makes routing everywhere). Both systems retain the silent e in dyeing, singeing, swingeing, to distinguish from dying, singing, swinging. In contrast, bathe and the British bath both form bathing. UK often whingeing, US less so; whinge is chiefly British. Both systems vary for tinge and twinge; both prefer cringing, hinging, lunging, syringing.

Before -able, UK prefers likeable, liveable, rateable, saleable, sizeable, unshakeable, [69] where US prefers to drop the -e; but UK as US prefers breathable, curable, datable, lovable, movable, notable, provable, quotable, scalable, solvable, usable,[70] and those where the root is polysyllabic, like believable or decidable. Both systems retain the silent e when necessary to preserve a soft c, ch, or g, as in traceable, cacheable, changeable; both retain e after -dge, as in knowledgeable, unbridgeable.

Both abridgment and the more regular abridgement are current in the US, only the latter in the UK.[71] Similarly for lodg(e)ment. Both judgment and judgement can be found everywhere, although the former strongly prevails in the US and the latter prevails in the UK[72] except in law, where judgment is standard. Similarly for abridgment. Both prefer fledgling to fledgeling, but ridgeling to ridgling.

The informal Briticisms moreish (causing a desire for more of something) and blokeish[73] usually retain e; more established words like slavish and bluish usually do not.

Different spellings, different connotations

artefact or artifact: In British usage, artefact is the main spelling and artifact a minor variant;[74] however, some speakers claim to write artefact to mean “a product of artisanry” but artifact when the meaning is “a flaw in experimental results caused by the experiment itself”[citation needed]. In American English, artifact is the usual spelling. Canadians prefer artifact and Australians artefact, according to their respective dictionaries.[75]

dependant or dependent: British dictionaries distinguish between dependent (adjective) and dependant (noun). In the US, dependent is usual for both noun and adjective, notwithstanding that dependant is also an acceptable variant for the noun form in the US.[76]

disc or disk: Traditionally, disc used to be British and disk American. Both spellings are etymologically sound (Greek diskos, Latin discus), although disk is earlier. In computing, disc is used for optical discs (e.g. a CD, Compact Disc; DVD, Digital Versatile/Video Disc) while disk is used for products using magnetic storage (e.g. floppy disk and hard disk; short for diskette).[77] For this limited application, these spellings are used in both the US and the Commonwealth.

enquiry or inquiry:[78] According to Fowler, inquiry should be used in relation to a formal inquest, and enquiry to the act of questioning. Many (though not all) British writers maintain this distinction; the OED, on the other hand, lists inquiry and enquiry as equal alternatives, in that order. Some British dictionaries, such as Chambers 21st Century Dictionary[4], present the two spellings as interchangeable variants in the general sense, but prefer inquiry for the "formal inquest" sense. In the US, only inquiry is commonly used. In Australia, inquiry and enquiry are often interchangeable, but inquiry prevails in writing. Both are current in Canada, where enquiry is often associated with scholarly or intellectual research.

ensure or insure: In the UK (and Australia), the word ensure (to make sure, to make certain) has a distinct meaning from the word insure (often followed by against – to guarantee or protect against, typically by means of an "insurance policy"). The distinction is only about a century old,[79] and this helps explain why in (North) America ensure is just a variant of insure, more often than not. According to Merriam-Webster's usage notes, ensure and insure “are interchangeable in many contexts where they indicate the making certain or [making] inevitable of an outcome, but ensure may imply a virtual guarantee <the government has ensured the safety of the refugees>, while insure sometimes stresses the taking of necessary measures beforehand <careful planning should insure the success of the party>[80] Canada follows the British distinction.[citation needed]

programme or program: The British programme is a 19th-century French version of program, which first appeared in Scotland in the 17th century and is the only spelling found in the US. The OED entry, written around 1908 and listing both spellings, said program was preferable, since it conformed to the usual representation of the Greek as in anagram, diagram, telegram etc. In British English, program is the common spelling for computer programs, but for other meanings programme is used. In Australia, program has been endorsed by government style for all senses since the 1960s,[82] although programme is also common; see also the name of The Micallef Program(me). In Canada, program prevails, and the Canadian Oxford Dictionary makes no meaning-based distinction between it and programme; many Canadian government documents use programme in all senses of the word also to match the spelling of the French equivalent.[83]

Compare also meter/metre, for which an older English written distinction between etymologically related forms with different meanings once existed, but was obviated in the regularization of American spellings.

Contractions, where the final letter is present, are often written in British English without stops/periods (Mr, Mrs, Dr, St). Abbreviations where the final letter is not present generally do take stops/periods (such as vol., etc., ed.); British English shares this convention with French: Mlle, Mme, Dr, Ste, but M. for Monsieur. In American English, abbreviations like St., Mr., Mrs., and Dr. always require stops/periods.

Miscellaneous spelling differences

UK

US

Remarks

adze

adze, adz

annexe

annex

To annex is the verb in both Commonwealth and American usage; however, when speaking of an annex(e) –the noun referring to an extension of a main building, not military conquest, which would be annexation–, it is usually spelled with an -e at the end in the Commonwealth (except Canada), but in the US it is not.

any more

anymore

In sense "any longer", the single-word form is usual in North America and Australia but unusual in the UK, at least in formal writing.[86] Other senses always have the two-word form; thus Americans distinguish "I couldn't love you anymore [so I left you]" from "I couldn't love you any more [than I already do]".

axe

ax, axe

Both noun and verb. The two-letter form is more etymologically conservative (the word comes from Old Englishæx).

camomile, chamomile

chamomile, camomile

In the UK, according to the OED, "the spelling cha- is chiefly in pharmacy, after Latin; that with ca- is literary and popular". In the US chamomile dominates in all senses. In Canada chamomile seems to prevail.

cheque

check

In banking. Hence pay cheque and paycheck. Accordingly, the North American term for what is elsewhere known as a current account or cheque account is spelled chequing account in Canada and checking account in the US. Some US financial institutions, notably American Express, prefer cheque.

chequer

checker

As in chequerboard/checkerboard, chequered/checkered flag, etc. Canada as US.[87]

In the US, both are used with donut indicated as a variant of doughnut.[88] In the UK, donut is indicated as a US variant for doughnut.[89]

draught

draft

The UK usually uses draft for all senses as a verb;[90] for a preliminary version of a document; for an order of payment (bank draft), and for military conscription (although this last meaning is not as common as in American English). It uses draught for drink from a cask (draught beer); for animals used for pulling heavy loads (draught horse); for a current of air; for a ship's minimum depth of water to float; and for the game draughts, known as checkers in the US. It uses either draught or draft for a plan or sketch (but almost always draughtsman in this sense; a draftsman drafts legal documents). The US uses draft in all these cases (although in regard to drinks, draught is sometimes found). Canada uses both systems; in Australia, draft is used for technical drawings, is accepted for the "current of air" meaning, and is preferred by professionals in the nautical sense.[91] The pronunciation is always the same for all meanings within a dialect (RP /drɑ:ft/, General American /dræft/). The spelling draught is older; draft appeared first in the late 16th century.[92]

Grey became the established British spelling in the 20th century, pace Dr. Johnson and others,[95] and is but a minor variant in American English, according to dictionaries. Canadians tend to prefer grey. Non-cognate greyhound is never grayhound.

jail, gaol

jail

Jail prevails everywhere, although gaol is still an official spelling in Australia; in the UK, gaol and gaoler are used, apart from literary usage, chiefly to describe a mediaeval building and guard. In Canada, gaol is historical.[citation needed]

kerb

curb

For the noun designating the edge of a roadway (or the edge of a [UK] pavement/[US] sidewalk/[Australia] footpath). Curb is the older spelling, and in the UK as in the US is still the proper spelling for the verb meaning restrain.[96] Canada as US.

liquorice

licorice

Licorice prevails in Canada and is common in Australia, but is rarely found in the UK; liquorice, which has a folk etymology cognate with liquor,[97] is all but nonexistent in the US. ("chiefly British", according to dictionaries).[98]

Neuron prevails[citation needed] in Canada and Australia; both are common in the UK.

omelette

omelet, omelette

Omelette prevails in Canada and Australia. The shorter spelling is older, despite the etymology (French omelette).[100]

phoney

phony

Originally an Americanism, this word made its appearance in Britain during the Phoney War.[101]

pyjamas

pajamas

Pronounced /-'dʒɑːməz/ in the UK, /-'dʒɑməz/ or /-'dʒæməz/ in the US. Canada has both.[102]

per cent

percent

plough

plow

Both date back to Middle English; the OED records several dozen variants. In the UK, plough has been the standard spelling for about three centuries.[103] Although plow was Webster's pick, plough continued to have currency in the US, as the entry in Webster's Third (1961) implies; newer dictionaries label plough "chiefly British". The word snowplough/snowplow, originally an Americanism, predates Webster's reform and was first recorded as snow plough. Canada has both plough and plow,[104] although snowplough is much rarer than snowplow.

sceptic (-al, -ism)

skeptic (-al, -ism)

The American spelling, akin to Greek, preferred by Fowler, and used by many Canadians, is the earlier form.[105]Sceptic also pre-dates the settlement of the US and follows the French sceptique and Latin scepticus. In the mid-18th century Dr Johnson's dictionary listed skeptic without comment or alternative but this form has never been popular in the UK;[106]sceptic, an equal variant in Webster's Third (1961), has now become "chiefly British". Australians generally follow British usage. All are pronounced with a hard "c", though in French the letter is effectively silent and so confusible with septique.

storey

storey, story

Level of a building. Note also the differing plural, storeys vs stories respectively.

sulphur

sulphur, sulfur

Sulfur is the international standard in the sciences (IUPAC), and is supported by the UK's RSC.[107]Sulphur was preferred by Johnson, is still used by British and Irish scientists and is still actively taught in British and Irish schools, prevails in Canada and Australia, and is also found in some American place names (e.g., Sulphur Springs, Texas and Sulphur, Louisiana). AmE usage guides suggest sulfur for technical usage, and both sulphur and sulfur in common usage.[108][109]

tyre

tire

The outer lining of a wheel, which contacts the road or rail and may be metal or rubber. Canada as US. Tire is the older spelling, but both were used in the 15th and 16th centuries (for a metal tire); tire became the settled spelling in the 17th century but tyre was revived in the UK in the 19th century for pneumatic tyres, possibly because it was used in some patent documents,[110] though many continued to use tire for the iron variety. The Times newspaper was still using tire as late as 1905.

vice

vise

The two-jaw tool. Americans (and Canadians) retain a medieval distinction between vise (the tool) and vice (the sin and the Latin prefix meaning "deputy"), both of which are vice in the UK (and Australia).[111]

yoghurt, yogurt

yogurt

Yoghurt is an also-ran in the US, as yoghourt is in the UK. Although Oxford Dictionaries have always preferred yogurt, in current British usage yoghurt seems to be preferred. In Canada yogurt prevails, despite the Canadian Oxford preferring yogourt, which has the advantage of being bilingual, English and French.[112] Australia as the UK. Whatever the spelling, the word has different pronunciations in the UK /jɒ-/ (or /jəʊ-/) and the US. /joʊ-/. Australia as US with regard to pronunciation. The word comes from the Turkishyoğurt.[113]; the letter ğ was traditionally rendered as gh in transliterations of Turkish, which used to be written in a variant of the Arabic alphabet until the introduction of the Latin alphabet in 1928.

↑In Webster's New World College Dictionary, scalawag is lemmatized without alternative, while scallawag and scallywag are defined by cross-reference to it; all of them are marked as originally American.

↑Although acre was spelled æcer in Old English and aker in Middle English, the acre spelling of Middle French was introduced in the 15th Century. Similarly, loover was respelled in the 17th Century by influence of the unrelated Louvre. (see OED, s.v. acre and louvre)

↑“The spelling sulfur predominates in United States technical usage, while both sulfur and sulphur are common in general usage. British usage tends to favor sulphur for all applications. The same pattern is seen in most of the words derived from sulfur.” Usage Note, Merriam-Webster Online. [Accessed 1 January 2008]

↑The contrasting spellings of the chemical elements Al and S mean that the American spelling aluminum sulfide becomes aluminum sulphide in Canada, and as aluminium sulphide in older UK usage.